RESUMEN
Chemotherapeutic drugs, such as cyclophosphamide, cause severe immunosuppression and patients become susceptible to infections. Based on this, the immunomodulatory potential of tarin, a lectin from Colocasia esculenta, was evaluated in bone marrow cell cultures and in cyclophosphamide-immunosuppressed mice. Tarin promoted maintenance of hematopoietic progenitors and repopulation of Gr1 cells in vitro which was supported by in vivo results. In immunosuppressed mice, tarin increased bone marrow cell numbers and altered cell profile distribution by enhancing the frequency of Gr1+ progenitors, including Ly6-CintLy6-Glo, and anticipating their proliferation/differentiation in mature cells, especially Ly6-CloLy6-Ghi. Bone marrow cells harvested from tarin-treated immunosuppressed mice proliferated in response to GM-CSF or G-CSF in vitro and, the low numbers of bone marrow cells in the G0 phase, combined with a high number cells undergoing apoptosis confirmed that tarin promoted a faster and intense proliferation/differentiation, even in the presence of CY-induced toxicity. As a result, tarin minimized leukopenia in immunosuppressed mice promoting a faster recovery of peripheral leucocytes and protected erythroid bone marrow cells from CY-cytotoxicity in a dose-dependent manner. Data suggest that tarin could be considered a potential adjuvant to decrease leukopenia and possibly ameliorate anemia, if carefully evaluated in human cancer cell lineages and in clinical trials.
Asunto(s)
Ciclofosfamida/farmacología , Globulinas/farmacología , Granulocitos/citología , Terapia de Inmunosupresión , Proteínas de Plantas/farmacología , Animales , Células de la Médula Ósea/citología , Recuento de Células , Muerte Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Forma de la Célula/efectos de los fármacos , Células Cultivadas , Células Clonales , Masculino , Ratones Endogámicos C57BL , Sustancias Protectoras/farmacologíaRESUMEN
Lectins are proteins found in a wide range of organisms, with the ability to bind reversibly to specific carbohydrates. They can display important biological activities, such as the activation of the cell cycle in lymphocytes. Storage proteins with lectin activity have been reported in tuberous plant species, such as Colocasia esculenta, popularly known as taro. A simple strategy based on Cibacron Blue chromatography was used to purify a 12 kDa polypeptide 1.3-fold, with a recovery of 30 %. The purified protein was identified as tarin by mass spectrometry, which indicated that it was present in G1a/G1d isoforms. Tarin exhibited both agglutinating activity against hamster erythrocytes and mitogenic activity in vitro and in vivo toward mouse splenocytes. Optimum cellular proliferation in vitro was achieved by 625 ng of the crude extract or 500 ng of the purified tarin. Total mouse splenocyte proliferation measured after 5 days of intraperitoneal inoculation of purified tarin was increased 3.3-fold in comparison to the control group. Half of the proliferating cells were identified as B lymphocytes by flow cytometry. These results show that this is an efficient and simple strategy to purify tarin and aid in establishing this protein as a new therapeutic drug, able to promote cell proliferation in a murine model.
Asunto(s)
Colocasia/química , Globulinas/aislamiento & purificación , Lectinas/aislamiento & purificación , Proteínas de Plantas/aislamiento & purificación , Animales , Ciclo Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Colocasia/genética , Cricetinae , Globulinas/química , Globulinas/farmacología , Lectinas/química , Lectinas/farmacología , Linfocitos/efectos de los fármacos , Ratones , Proteínas de Plantas/química , Proteínas de Plantas/farmacología , Bazo/citología , Bazo/efectos de los fármacosRESUMEN
BACKGROUND: There is increasing interest in non-pharmacological control of cholesterol and triglyceride levels in the plasma and diet-drug association represent an important area of studies. The objective of this study was to observe the hypocholesterolemic effect of soybean ß-conglycinin (7S protein) alone and combined with fenofibrate and rosuvastatin, two hypolipidemic drugs. METHODS: The protein and drugs were administered orally once a day to rats and the effects were evaluated after 28 days. Wistar rats were divided into six groups (n = 9): hypercholesterolemic diet (HC), HC+7S protein (300 mg.kg-1 day-1) (HC-7S), HC+fenofibrate (30 mg.kg-1 day-1)(HC-FF), HC+rosuvastatin (10 mg.kg-1 day-1)(HC-RO), HC+7S+fenofibrate (HC-7S-FF) and HC+7S+rosuvastatin (HC-7S-RO). RESULTS: Animals in HC-7S, HC-FF and HC-RO exhibited reductions of 22.9, 35.8 and 18.8% in total plasma cholesterol, respectively. In HC-7S-FF, animals did not show significant alteration of the level in HC+FF while the group HC-7S-RO showed a negative effect in comparison with groups taking only protein (HC-7S) or drug (HC-RO). The administration of the protein, fenofibrate and rosuvastatin alone caused increases in the plasma HDL-C of the animals, while the protein-drug combinations led to an increase compared to HC-FF and HC-RO. The plasma concentration of triacylgycerides was significantly reduced in the groups without association, while HC-7S-FF showed no alteration and HC-7S-RO a little reduction. CONCLUSION: The results of our study indicate that conglycinin has effects comparable to fenofibrate and rosuvastatin on the control of plasma cholesterol, HDL-C and triacylglycerides, when given to hypercholesterolemic rats, and suggests that the association of this protein with rosuvastatin alters the action of drug in the homeostasis of cholesterol.
Asunto(s)
Anticolesterolemiantes/farmacología , Antígenos de Plantas/farmacología , Proteínas en la Dieta/farmacología , Fenofibrato/farmacología , Fluorobencenos/farmacología , Globulinas/farmacología , Glycine max , Pirimidinas/farmacología , Proteínas de Almacenamiento de Semillas/farmacología , Proteínas de Soja/farmacología , Sulfonamidas/farmacología , Animales , Anticolesterolemiantes/aislamiento & purificación , Anticolesterolemiantes/uso terapéutico , Antígenos de Plantas/aislamiento & purificación , Antígenos de Plantas/uso terapéutico , Colesterol/sangre , Colesterol/metabolismo , Dieta Alta en Grasa/efectos adversos , Proteínas en la Dieta/aislamiento & purificación , Proteínas en la Dieta/uso terapéutico , Combinación de Medicamentos , Sinergismo Farmacológico , Fenofibrato/uso terapéutico , Fluorobencenos/uso terapéutico , Globulinas/aislamiento & purificación , Globulinas/uso terapéutico , Corazón/efectos de los fármacos , Hipercolesterolemia/sangre , Hipercolesterolemia/tratamiento farmacológico , Hipercolesterolemia/etiología , Hígado/efectos de los fármacos , Hígado/metabolismo , Hígado/patología , Masculino , Miocardio/patología , Tamaño de los Órganos/efectos de los fármacos , Pirimidinas/uso terapéutico , Ratas , Ratas Wistar , Rosuvastatina Cálcica , Proteínas de Almacenamiento de Semillas/aislamiento & purificación , Proteínas de Almacenamiento de Semillas/uso terapéutico , Proteínas de Soja/aislamiento & purificación , Proteínas de Soja/uso terapéutico , Sulfonamidas/uso terapéutico , Triglicéridos/sangre , Triglicéridos/metabolismoRESUMEN
BACKGROUND: Amaranth 7S globulin is a minor globulin component and its impact on the properties of an amaranth protein ingredient depends on its proportion in the variety of amaranth being considered. Some physicochemical, functional and angiotesin I-converting enzyme (ACE) inhibitory properties of amaranth vicilin were studied in this work and compared with the 11S globulin. RESULTS: Fluorescence spectroscopy results indicated that 7S globulin tryptophans were more exposed to the solvent and, by calorimetry, the 7S globulin denaturation temperature (T(d) ) was found lower than the 11S globulin T(d) , suggesting a more flexible structure. The 7S globulin surface hydrophobicity was higher than that of the 11S globulin, which is in agreement with the better emulsifying properties of the 7S globulin. The solubility in neutral buffer of the 7S globulin (851 ± 25 g kg(-1) ) was also higher than that of the 11S globulin (195 ± 6 g kg(-1) ). Bioinformatic analyses showed the presence of ACE inhibitory peptides encrypted in 7S tryptic sequences and peptides released after in vitro gastrointestinal digestion showed a high ACE-inhibitory capacity (IC(50) = 0.17 g L(-1) ), similar to that of 11S globulin peptides. CONCLUSION: Compared with the 11S globulin, the 7S globulin presents similar ACE inhibitory activity and some functional advantages, better solubility and emulsifying activity, which suits some food requirements. The functional behavior has been related with the structural properties.
Asunto(s)
Amaranthus/metabolismo , Inhibidores de la Enzima Convertidora de Angiotensina/farmacología , Globulinas/farmacología , Proteínas de Plantas/farmacología , Amaranthus/química , Amaranthus/genética , Inhibidores de la Enzima Convertidora de Angiotensina/química , Regulación de la Expresión Génica de las Plantas/fisiología , Globulinas/genética , Globulinas/metabolismo , Interacciones Hidrofóbicas e Hidrofílicas , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Espectrometría de FluorescenciaRESUMEN
The kinetics of thermal inactivation of A. terreus alpha-rhamnosidase was studied using the substrate p-nitrophenyl alpha-L-rhamnoside between 50 degrees C and 70 degrees C. Up to 60 degrees C the inactivation of the purified enzyme was completely reversible, but samples of crude or partially purified enzyme showed partial reversibility. The presence of the product rhamnose, the substrate naringin, and other additives reduced the reversible inactivation, maintaining in some cases full enzyme activity at 60 degrees C. A mechanism for the inactivation process, which permitted the reproduction of experimental results, was proposed. The products rhamnose (inhibition constant, 2.1 mM) and prunin (2.6 mM) competitively inhibited the enzyme reaction. The maximum hydrolysis of supersaturated naringin solution, without enzyme inactivation, was observed at 60 degrees C. Hydrolysis of naringin reached 99% with 1% naringin solution, although the hydrolysis degree of naringin was only 40% due to products inhibition when the initial concentration of flavonoid was 10%. The experimental results fitted an equation based on the integrated Michaelis-Menten's, including competitive inhibition by products satisfactorily.